As a preface, ICS works perfectly fine. I can connect to the internet through my wireless router with no problems. The problem, is that I can not access any MSN services or websites I believe as a result of the MTU setting. So now we continue with some terminal output...

As you can see, the MTU is currently set to 1500. The optimal MTU for PPOE ADSL connections is 1492. I believe that the host ICS computer is set to 1492; however, I will need to get back to you guys on that one. The current symptoms on the target I8200 machine are as stated, no access to msn services, and a seemingly slower connection over time. I have been googling for some time on changing the MTU with little success.

My current config files that are applicable:

/etc/conf.d/net

-I know this is not set up right at the moment. I'm learning.

Code:

# This blank configuration will automatically use DHCP for any net.*
# scripts in /etc/init.d. To create a more complete configuration,
# please review /etc/conf.d/net.example and save your configuration
# in /etc/conf.d/net (this file :]!).

# It's important that we tell wpa_supplicant which driver we should
# be using as it's not very good at guessing yet

/etc/wpa_supplicant/wpa_supplicant.conf

Code:

# This is a network block that connects to any unsecured access point.
# We give it a low priority so any defined blocks are preferred.
# The below line not be changed otherwise we refuse to work
ctrl_interface=/var/run/wpa_supplicant

# Ensure that only root can read the WPA configuration
ctrl_interface_group=0

These are the only applicable config files I know of for a wireless connection. I orginally thought it may be my Marvell driver as the chipset has a bad reputation, but I have installed Ubuntu on this machine with the same exact ICS setup without problems. All msn websites and messenger worked fine. I cannot verify the MTU setting on my Ubuntu install, as Gentoo has since replaced it. Thus, I am convinced the problem lies in this configuration, as the rest of the network has not changed.

I have probably forgotten something, so let me know and I'll post more information. I wrote this in a hurry. Anyway, does anyone know how to change the MTU setting on a Gentoo install as outlined above?

Thanks in advance

Wow. I just noticed my registration date. I had no idea that I even had an account here. I just began using linux in the past year. Anyway, no matter.

Devcon

11-15-2008 01:53 AM

I'm a bit closer, but I still cannot find where to change the mtu setting. Is it even possible from within /conf.d/net? An update...

Code:

GNU nano 2.1.5 File: /etc/conf.d/net

# This blank configuration will automatically use DHCP for any net.*
# scripts in /etc/init.d. To create a more complete configuration,
# please review /etc/conf.d/net.example and save your configuration
# in /etc/conf.d/net (this file :]!).

It connect to my ICS network fine, but I still cannot connect to certain sites such as microsoft ones. I know I need to change the MTU. I thought the /init.d/net.wlan0 script might have an option. It refers to mtu in one section:

Code:

# Calculates the best metric for the interface
# We use this when we add routes so we can prefer interfaces over each other
calculate_metric() {
local iface="$1" metric="$2"

This appears to be the area where ifconfig is spitting out that invalid argument error.

Code:

#/lib/rcscripts/net/ifconfig.sh

# bool ifconfig_pre_start(char *interface)
#
# Runs any pre_start stuff on our interface - just the MTU atm
# We set MTU twice as it may be needed for DHCP - a dhcp client could
# change it in error, so we set MTU in post start too
ifconfig_pre_start() {
local iface="$1"

Is there a bug in this part of the script? Or, does this only work with wired interfaces or ones which do not use ndiswrapper?

Devcon

11-16-2008 01:59 PM

I'm going to mark this solved, although I wish I had a more detailed evaluation of the specific setting in question.

I was using kernel 2.6.27 vanilla that I had compiled myself. Downloading the new kernel 2.6.27.6 and recompiling has fixed the problem. I did not make any significant changes to the networking config portion of menuconfig.

I'll try to do a more in depth analysis of the difference between my previous kernel config and the present one.

kaddy

04-21-2009 02:30 AM

I was looking for solving something earlier and stumbled across this posting, anyways, solution to the manually setting MTU issue is as follows: